Preparation And Characterization Of New Trans-polyisoprene Latex

This paper mainly studies a new type of low crystal degree trans polyisoprene latex prepared by high content of trans polyisoprene,which investigated from three aspects of emulsifier system,emulsification formula and emulsification process.The emulsifier formula and emulsification process are optimized at the same time respectively.It obtained new type of trans polyisoprene latex with high performance and much more stability that prepared from the determination of emulsifier formula and emulsification process.The effect of emulsification process on the structure and crystal degree of trans polyisoprene latex is analyzed by characteristed the structure of new type of trans polyisoprene latex.The mixture of disproportionated potassium rosin and twelve alkylbenzene sulfonate was used as emulsifier,when the compound ratio was 2:1,the dosage of the compound was 5% of aqueous phase mass fraction,the amount of polyethylene glycol 6000 that was used as the stabilizer in this system was 0.1% of aqueous phase mass fraction,and the p H of the aqueous phase was adjusted to 12.The average particle size of latex particles is about 300 nm.When the mass concentration of latex is 5%,the mass ratio of oil to water is 1:1.5.In the preparation stage of trans polyisoprene solution,the constant temperature was heated to 70?and the stiring rate of the magnetic force agitator can be reached 800r/min,it is competely dissolved when the dissolved time reached 24 hours.When emulsified,the oil phase was added slowly to the aqueous phase,and the speed reached 6000 rpm.Under the action of the high shearing dispersing emulsifier,the emulsifying time was controlled at 10 min.During the dissolvent process of the prepared trans polyisoprene latex,the rotary evaporator was distilled at the pressure of-0.03~-0.08 MPa,TPI latex has much more excellent performance prepared by distilling at 40 oC and the distilled demulsification rate was low.The ratating speed of centrifuge reached at 8000r/min and the time was controlled as 10 min during the concentration process of the preparation of trans polyisoprene latex.The effect of centrifugal concentration discovered much better and the average particle size of latex was distributed around 600 nm and the solid content generally reached at 45%.It is clear from the results that the crystalline form of t he trans polyisoprene latex particles has retained the unique properties originated from the crystallization of the TPI material,which is a new latex particle different from the natural latex.